He clasped his hands behind his head, giving her an unobstructed view of his body.
Having already in various ways put before you his skull, spout-hole, jaw, teeth, tail, forehead, fins, and divers other parts, I shall now simply point out what is most interesting in the general bulk of his unobstructed bones.
But supplementary to this, it has hypothetically occurred to me, that as ordinary fish possess what is called a swimming bladder in them, capable, at will, of distension or contraction; and as the Sperm Whale, as far as I know, has no such provision in him; considering, too, the otherwise inexplicable manner in which he now depresses his head altogether beneath the surface, and anon swims with it high elevated out of the water; considering the unobstructed elasticity of its envelope; considering the unique interior of his head; it has hypothetically occurred to me, I say, that those mystical lung-celled honeycombs there may possibly have some hitherto unknown and unsuspected connexion with the outer air, so as to be susceptible to atmospheric distension and contraction.
An unobstructed view of the great mountain is rarely obtained, however, because of the mists and clouds which cover its cone.
According to the undulatory theory the light cannot be regarded strictly as travelling along a ray; but the existence of an unobstructed ray implies that the system of Fresnel's zones can be commenced, and, if a large number of these zones are fully developed and do not terminate abruptly, the illumination is unaffected by the neighbourhood of obstacles.
If it be made in the unobstructed air, especially if it descend to its mark, the stroke is then simply irresistible.
This rise and fall of Walden at long intervals serves this use at least; the water standing at this great height for a year or more, though it makes it difficult to walk round it, kills the shrubs and trees which have sprung up about its edge since the last rise--pitch pines, birches, alders, aspens, and others--and, falling again, leaves an unobstructed shore; for, unlike many ponds and all waters which are subject to a daily tide, its shore is cleanest when the water is lowest.